Damping means for indicating instruments



Dec. 31, 1940. a FISCHEL 2,226,902

DAIPING MEANS FORINDICATING INSTRUMENTS Filed April 11. 1939 Z5 I 24 F I g 4 INVENTQi M BY Patented Dec. 31, 1940 UNITED STATES DAMPING MEANS FOR. INDICATING INSTRUMENTS Eduard Fischel, Berlin-Charlottenburg, Germany, assignor to Siemens Apparate und Maschinen Gesellschaft mit beschrankter Haftung, Berlin, Germany, a corporation of Germany Application April 11, 1939, Serial No. 267,350 In Germany April 14, 1938 1 Claim. (Cl. 74-5) This invention relates to damping means, and more particularly to damping means for measuring. indicating or control instruments.

One of the objects of the present invention is to provide novel damping means which are simple and light in construction and inexpensive to manufacture.

Another object of the invention is to provide novel means of the above character which funcau tion with uniformity and which will not reduce the accuracy of an apparatus to which it is operatively connected- Another object is'to provide novel damping means for measuring, indicating or control instruments, the latter having a movable member to be damped which is in constant vibration.

A further object of the invention is to provide novel damping means which concurrently act as electric control means.

go The above and further objects and novel features wiil more fully appear from the detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing 5 is for purposes of illustration only and is not intended as a definition of the limits of the invention, reference for this latter purpose being had to the appended claim.

In the drawing, wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is a perspective view of one embodiment of the invention;

Fig. 2 is a detailview of a portion of Fig. l:

Fig. 3 is a bottom view of a damping arrangement comprising a second embodiment of the invention; and,

Fig. 4 is a side elevation of the parts shown in Fig. 3.

In the form shown in Fig. 1, the apparatus is employed for damping the movements of a control system comprising a measuring device, for example a turn indicator for an aircraft, which is constituted by a gyro rotor III in gimbal frame suspension. The gimbal frame suspension is constituted by a frame II having trunnions I2, the coincident axes of which are perpendicular to the axis of rotation of rotor I0. Trunnions I2 are rotatably mounted in fixed bearings I3.

Suitable means are provided for damping any oscillatory movement of the gyro, comprising two members which frictionally engage one another, the first member, for example, being constituted by an arm 14 which is rigidly attached to one of the trunnions I2, the latter being normally retained in a central position by means of resilient spring members I5. Arm IQ is provided, adjacent the free extremity thereof, with a leaf or laminated spring Iii with which is associated, in a manner to appear later, a cap-shaped friction member I1 which engages a second friction member I8 under the pressure of Spring I6. Member III, in the embodiment illustrated, is fixedly mounted relative to arm I4, for example by brackets 19, which are secured to the craft. In order to regulate the intensity of the frictional engagement between members I! and ii, a set screw 20 is provided within leaf spring I6 which passes therethrough and engages a 15 depending portion Md of the arm I4.

For the purpose of bringing about a uniform pressure of the member I 1 against member I8, the first-named member is associated with leaf spring i5 by means of a ball and socket joint 20 comprising, in the form shown in Fig.2, a ball H which engages a perforation 22 at the extremity of said spring, ball 2| being attached to member I! which is tubular in form.

In order that an instrument of the above 25 character may govern a control magnitude, for example, an electric current, suitable current control means can be employed therewith comprising, for example, an electric resistance element with which is associated a sliding member 80 or contact arm. Such a resistance and sliding contact can be used in the present invention not only as a current control device but also as a damper. In the form shown in Fig. 3, a first friction member comprises a sliding resistance 35 contact 23 which is preferably rigidly attached to leaf spring I6, and which frictionally engages an elastic or yielding strip 24 of high conductivity. Strip 24 is stretched above a high ohmic resistance 25 between arm 26, 21 and is pressed go into, contact with the resistance by the pressure of spring I6. Resistance 25 may be constituted by a graphite or carbon layer. The friction resulting from the movement of the sliding contact 23 on the resistance member serves 45 in a manner analogous to that above described for damping the control instrument.

There is thus provided a novel damping device which is easily adapted for use in combination with a wide.variety of apparatus, in particular measuring or indicating devices, wherein a damping action is needed for some member thereof.

Although only two embodiments of the invention have been illustrated and describ 'l in deits tail, it is to be expressly understood that the first axis, means yieldingly opposing the angular came is not limited thereto; for example, the movement of said gimbal about said second axis fwo friction members may be of any desired whereby the angle of movement is a. function form. Various changes may be made in the deof the rate of turn of said aircraft, an arm insign and arrangement of the parts without decluded in said yieldingly opposing means conparting from the spirit and, scope of the -inven nec'tied with'f a'id gimba- "fat th' x is o tion, as the same'will'nowbe understood by'" those ment of "said gimbal for angular movementskilied in the art. For a definition of the limits, therewith, a first friction member, a staof the invention, reference will be had primarily tionaryr-i'ction member, and resilient means to the appended claim. H first fri ction member to said What is claimed is: movement therewith and yield- A rate of turn responsive gyroscope for anair craft, comprising a rotor, a gimbaipmounti'ng said rotor for spinning about a hori z ontafjaxi said gimbal being mounted for angular mo ment about a s'econd axis perpendicular to the 'csxfl ii be-innom vloeisaoi are lit anomzzur'i' 23a, 'isin we grsiqmeb r01 behivoiq 8'15; anssm eic sii 1 moths animus-ab e griiaimrnoo ,DXVIE add in iiiemeve-"fi wot-slit free rem eno egsgne vlisrroiisirz rioidw a (imam ow: I'Z'XJOfjiit a gated ,eiqmsxe "mi. ,ieeireom evaii nolil barium-is vibigir a! la -2 511s 

